Thermo-siphonic cooling circuit and circuit breaker

ABSTRACT

Power station switch in which the gas under pressure in the cutout chamber is made to flow and passes in a radiator type heat exchanger, characterised in that the cold air is made to flow past the radiator type heat exchanger by a static device receiving heated air drawn off from the general cooling circuit within the protective casing of the switch.

United States Patent [191 Thuries 1 Nov. 12, 1974 1 THERMO-SIPHONIC COOLING CIRCUIT AND CIRCUIT BREAKER [75] Inventor:

[73] Assignee: Delle-Alsthom, Villeurbannc, France [22] Filed: Sept. 7, 1973 [21] Appl. No.: 395,115

Edmond Thuries, Pusignan, France [30] Foreign Application Priority Data Sept. 8, 1972 France 72.31901 [52] U.S. Cl 200/289, 317/100, 200/148 R, 174/15 R, 165/128 [51] Int. Cl. I'IOlh l/62, HOlh H64 [58] Field of Search 200/166 K, 148 R, 148 B, 200/289; 165/128; 174/15 R, 16 R; 317/100,

[56] References Cited UNITED STATES PATENTS 2,501,812 3/1950 Fodor 165/128 3,214,544 10/1965 Leeds 317/100 3,221,129 11/1965 Young 200/148 B 3,407,869 10/1968 Staunton 317/100 3,602,856 8/1971 White 174/15 R Primary E.\'aminerRobert K. Schaetcr Assistant Eruminer-Gerald P, Tolin Attorney, Agent, or Firm-Sughruc, Rothwcll, Mion, Zinn & Macpeok [57] ABSTRACT Power station switch in which the gas under pressure in the cut-out chamber is made to flow and passes in a radiator type heat exchanger, characterised in that the cold air is made to flow past the radiator type heat exchanger by a static device receiving heated air drawn off from the general cooling circuit within the protec tive casing of the switch.

4 Claims, 1 Drawing Figure PATENTEL NUV l 2 I974 Jvlilqllll A Ln mmm THERMO-SIPHONIC COOLING CIRCUIT AND CIRCUIT BREAKER DESCRIPTION OF THE PRIOR ART A power station switch (cut-out switch or coupling switch) having a high rated current, in which the cooling of the main contacts is obtained by the flow of compressed gas in the cut-out chamber is frequently used in a power station. This compressed gas is cooled by a radiator type heat exchanger in which the dissipating of the calories in ensured by the flowing of a fluid distinct from the compressed gas in the cut-out chamber, for example by air set in motion by one or several ventilators generally situated on the outside of a protective casing in which the switch is installed and inside which a general air flow for cooling the power station is produced. But the use of ventilators has the drawback of requiring the maintenance of these devices and of their control elements. According to the present invention, due to a drawing off of the hot air flowing in the protective casing, a static device makes cold air on the outside of the casing flow in the radiator type heat-exchanger and ensures the cooling of the compressed gas in the cut-out chamber.

SUMMARY OF THE INVENTION This addition thus has for its object a power station switch having a high rated current, which comprises a cut-out chamber containing a gas under pressure, which is situated in a protective casing inside which a first cut-out chamber cooling air flow is produced and in which the said gas under pressure is made to flow permanently by means outside thecut-out chamber, these means comprising a radiator type heat exchanger situated on the outside of the protective casing and cooled by cold air, forming a second, radiator cooling air flow characterised in that it comprises means for drawing off a portion of the first cooling air flow produced in the protective casing and means for using that drawing off for setting in motion, the said cold air.

The portion of cooling air flow produced in the protective casing drawn off for the purpose of setting in motion the cold air is, to great advantage, comprised between one per thousand and ten per cent.

BRIEF DESCRIPTION OF THE DRAWING An example of embodiment of the invention will be described by means of the accompanying FIGURE, which is a diagrammatic crosssection, in a vertical plane, of a power station switch assembly.

The input conductor 1 and output conductor 2 of the switch, as well as the contacts and the cut-out elements of the latter not shown, arranged inside a cover 3, are situated inside a protective casing 4. The cover 3 is supported by hollow support insulators 5 and 6 which insulate the cover 3 from the protective casing 4. These insulators 5 and 6 are extended by a harness 7 of metal tubes constituting the high-pressure circuit of a radiator type heat exchanger. The tube assembly 7 is arranged in series and its ends are connected to the insulators 5 and 6. The compressed gas ensuring the cut-out of the current in the switch flows in the form of a closed loop inside the cover 3, the insulators 5 and 6 and the tubes 7. The tube harness 7 is arranged inside an enclosure 8 open at both its ends 9 and 10. In a zone 11, comprised between the tubes 7 and the end 10 and generally having a smaller diameter, like the end 10, than the enclosure assembly 8, enters a pipe 12. The latter directs hot air drawn off from the protective casing 4 towards the end 10 of the enclosure 8, by means of deflector flaps 13. The end 14 of the pipe 12 comprises, preferably, a hot air flow guide element.

The operation of the device is as follows. The cut-out chamber cooling air flowing inside the casing 4 and heated by the losses in the conductors l and 2 and in the switch arranged in the cover 3, is divided into two flows: the flow having a greater discharge rate flows in the direction of the arrow 15 and continues to cool the casing, whereas a drawing off current 16, produced by means of the deflector flaps 13, enters the pipe 12 and leaves the latter through the guiding element 14, in the direction 17. By siphon effect, that hot air draws off the cold air, which crosses through the enclosure 8, entering through the opening 9, in the direction of the arrow, 18 and leaving through the opening 10 in the direction of the arrow 19. By means of the radiator type heat exchanger, the air in the enclosure 8 cools the compressed gas, in the cut-out chamber, flowing in the tubes 7.

The device for cooling the compressed gas of the switch according-to the invention has the advantage of not comprising any moving part and this simple static device considerably reduces maintenance.

I claim: 1. In a power station switch having a high rated current and which comprises:

a closed cut-out chamber containing a gas under pressure, said chamber being situated within a protective casing with a first cooling air flow passing between said chamber and said casing to provide for cooling of said chamber, a radiator type heat exchanger external to said casing and in closed fluid loop connection with said chamber for circulating said gas under pressure therebetween, an enclosure surrounding said radiator type heat exchanger and defining with said heat exchanger a second cooling air flow path passing therethrough and across said heat exchanger to remove heat therefrom, the improvement comprising: means for drawing off a portion of said first air flow from said casing, downstream of the initial contact area of said first cooling air flow with said chamber and after heating thereof, and

means for using the heated drawn off air for setting in motion a second air flow within said second cooling air flow path, around said radiator type heat exchanger.

2. The power station switch according to claim 1, wherein said drawing off means comprises conduit means connecting said casing to said enclosure downstream of said radiator and deflector flap means for controlling the flow area leading from said easing into said conduit.

3. The power station switch according to claim 1, wherein said means for using said drawn off air comprising a siphon.

4. The power station switch according to claim 1, wherein that portion of the cooling air flow produced in the casing which is drawn off for setting up said second air flow comprises between one per thousand and ten per cent. 

1. In a power station switch having a high rated current and which comprises: a closed cut-out chamber containing a gas under pressure, said chamber being situated within a protective casing with a first cooling air flow passing between said chamber and said casing to provide for cooling of said chamber, a radiator type heat exchanger external to said casing and in closed fluid loop connection with said chamber for circulating said gas under pressure therebetween, an enclosure surrounding said radiator type heat exchanger and defining with said heat exchanger a second cooling air flow path passing therethrough and across said heat exchanger to remove heat therefrom, the improvement comprising: means for drawing off a portion of said first air flow from said casing, downstream of the initial contact area of said first cooling air flow with said chamber and after heating thereof, and means for using the heated drawn off air for setting in motion a second air flow within said second cooling air flow path, around said radiator type heat exchanger.
 2. The power station switch according to claim 1, wherein said drawing off means comprises conduit means connecting said casing to said enclosure downstream of said radiator and deflector flap means for controlling the flow area leading from said casing into said conduit.
 3. The power station switch according to claim 1, wherein said means for using said drawn off air comprising a siphon.
 4. The power station switch according to claim 1, wherein that portion of the cooling air flow produced in the casing which is drawn off for setting up said second air flow comprises between one per thousand and ten per cent. 